Add some keys to elements

plugins/woocommerce-blocks/assets/js/products-block.js

@@ -552,7 +552,7 @@ var ProductPreview = function (_React$Component4) {
 
 			return wp.element.createElement(
 				'div',
-				{ className: 'product-preview' },
+				{ className: 'product-preview', key: product.id + '-preview' },
 				image,
 				wp.element.createElement(
 					'div',
@@ -1802,7 +1802,7 @@ var ProductSpecificSelectedProducts = withAPIData(function (props) {
 
 		productElements.push(wp.element.createElement(
 			'li',
-			{ className: 'wc-products-list-card__item' },
+			{ className: 'wc-products-list-card__item', key: productData.id + '-specific-select-edit' },
 			wp.element.createElement(
 				'div',
 				{ className: 'wc-products-list-card__content' },

plugins/woocommerce-blocks/assets/js/products-block.jsx

@@ -340,7 +340,7 @@ class ProductPreview extends React.Component {
 		}
 
 		return (
-			<div className="product-preview">
+			<div className="product-preview" key={ product.id + '-preview' } >
 				{ image }
 				<div className="product-title">{ product.name }</div>
 				<div className="product-price" dangerouslySetInnerHTML={ { __html: product.price_html } } />

plugins/woocommerce-blocks/assets/js/views/specific-select.jsx

@@ -337,7 +337,7 @@ const ProductSpecificSelectedProducts = withAPIData( ( props ) => {
 			const productData = PRODUCT_DATA[ productId ];
 
 			productElements.push(
-				<li className="wc-products-list-card__item">
+				<li className="wc-products-list-card__item" key={ productData.id + '-specific-select-edit' } >
 					<div className="wc-products-list-card__content">
 						<img src={ productData.images[0].src } />
 						<span className="wc-products-list-card__content-item-name">{ productData.name }</span>